Separator for storage-battery couples.



w. A. CROWDUS.

SEPARATOR FOR STORAGE BATTERY COUPLES. APPLICATION min JAN. 11. I916- 1,217,573. Patented Feb. 27, 1917;

7755a arawda/J,

Improvement in Battery Couples,

a specification.

UNITED S ATES PATENT OFFICE.

WALTER CROWDUS, 0F CHICAGO,"ILI4INO IS, ASSIGNOR 'JEO -TOHN P. MENTZER, OI

CHICAGO, ILLINOIS.

SEPARATOR FOR STORAGE-BATTERY conrnns. 1

To all whom may concern:

Be it known that I, WALTER A. Cnowous,

a citizen of the United States, residing 'at of Illinois, have invented a new and useful Separators for Storageof which the following is The primary object of my invention is to provide a separator for interposition be- 4 tween the metallic'elements of a storagebattery, which shall be highly absorbent of the liquid electrolyte and durable because of its property of efi'ectually resisting carbonization bythe action of the battery electrolyte,

I have discovered that lignin, in a more or less pure state, possesses these advantages ina preeminent degree,'and afl'ords a superior separator for use in storage-batteri'es. v To obtainthe pure or practically purelignin, I select a suitable wood, preferably other than a coniferous variety,'and from old trees, since-the older the tree the richer it is in lignin. This wood is reduced, as by grinding, to a fine or impalpable powder, and is heated, as a pulp, in a digester with a strong solution of caustic soda in water until the non fibrous constituents of the wood .are completely dissolved.- The best result is obtained by digesting the pulp with superheated dry steam under pressure-say of two or more atmospheres-whereby the generated carbonic-acid gas is removed to a suflicient extentto render the lignin-pulp, bleached. to'.whiteness, non-carbonizing by the action of the battery electrolyte. This I treatment takes about 10 hours. When it 'is completed, the solid matter, after separating from it .the solutioncontaining the constituents'dissolved out of the pulp, is

washed with water to thoroughly remove the alkali andany of the other matter that may'adhere to or be mixed with it. p

. tically' free from any of the other uents of the treated wood..

Specification o'f'Letters Patent.

In this manner lignin' is obtained prac- 1 Patented Feb. 27, 1917.

I I Application filed January 11, 1916. Serial No. 71,477.

In the accompanying drawing, I*i ure 1 is a broken plan view of my improved separator in the form of'a sheet, and Fig. 2 is an enlarged section online 2, Fig. 1.

It is preferred to provide my improved separator A in porous-sheet form, and thisv may be done by the well-known procedure that is commonly practised inmanufacturing paper to felt it into sheets of desired thickness, which are thereupon dried; and

proper lengthand width to form storagebattery separators.

. The all important advantage ofmy im- "the sheets thus produced may be cut into proved separator thus made from wood-pulp treated to obtain, as the product, practically pure lignin, or, at least, to' render the product poor in cellulose constltuents and rich in lignin, lies in its property of resisting ca'rbonization and dissolution by the electro-. lytic action in a battery-cell. Cellulose beiarities of cellulose, from which my improved article is .to be distinguished, de-

tract from its usefulness as an absorbent separator in a storage-battery.

. YVhat I claim as new and desire to'secure by Letters Patent is ing a carbohydrate, isomerous with starch A separator for the metallic elements in a storage battery, consisting of a flexible,

absorbent sheet-formed of finely pulverized lignin, from which the carbonizing constituents of the wood have been practically all removed.v g WALTER A. CROWDUS.

In presence of- A. C. F soman,

D. C. THORSEN." 

